Comprehensive coverage of the special theory (frames of reference, Lorentz transformation, relativistic mechanics of mass points, more), the general theory ...

In recent years, observational techniques at cosmological distances have been sufficiently improved that cosmology has become an empirical science, rather than a field for unchecked speculation. There remains the fact that its object, the whole universe, exists only once; hence, we are unable to separate “general” features from particular aspects of “our” universe. This might not be a serious drawback if we were justified in the belief that presently accepted laws of nature remain valid on the cosmological scale. In the (...) author's opinion, however, there are grounds for doubting that belief. The three arguments presented are (1) the possibility that apparent constants of nature may, during cosmological times, turn out to vary (Dirac conjecture); (2) the effective breakdown of the principle of relativity caused by the effects of the cosmological environment on local experiments; and (3) the fact that present theory leads to field singularities at the early stages of the expanding universe, which might be a signal that currently accepted theoretical concepts are inadequate for an understanding of highly condensed matter. (shrink)

In preparation for the treatment of the gravitational field at spatial infinity, this paper deals with the electromagnetic field at spatial infinity. The field equations on this three-dimensional(1+2) manifold can be obtained from an action principle, which in turn lends itself to a Hamiltonian formulation. Quantization is formally straightforward, but some thought is given to the physical interpretation of the results.

This paper treats the formulation of the gravitational field variables and the equations obeyed by them at spatial infinity. The variables consist of a three-dimensional tensor and a scalar, which satisfy separate field equations, which in turn can be obtained from two distinct Lagrangians. Aside from Lorentz rotations, the symmetry operations include an Abelian gauge group and an Abelian Lie group, leading to a number of conservation laws and to differential identities between the field equations.